// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// DataPack represents a read-only view onto an on-disk file that contains
// (key, value) pairs of data.  It's used to store static resources like
// translation strings and images.

#ifndef UI_BASE_RESOURCE_DATA_PACK_H_
#define UI_BASE_RESOURCE_DATA_PACK_H_

#include <stddef.h>
#include <stdint.h>

#include <map>

#include "base/files/file.h"
#include "base/files/memory_mapped_file.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "base/strings/string_piece.h"
#include "ui/base/resource/data_pack_export.h"
#include "ui/base/resource/resource_handle.h"

namespace base {
class FilePath;
class RefCountedStaticMemory;
}

namespace ui {
enum ScaleFactor : int;

class UI_DATA_PACK_EXPORT DataPack : public ResourceHandle {
public:
    explicit DataPack(ui::ScaleFactor scale_factor);
    ~DataPack() override;

    void set_has_only_material_design_assets(bool has_only_material_assets)
    {
        has_only_material_design_assets_ = has_only_material_assets;
    }

    // Load a pack file from |path|, returning false on error.
    bool LoadFromPath(const base::FilePath& path);

    // Loads a pack file from |file|, returning false on error.
    bool LoadFromFile(base::File file);

    // Loads a pack file from |region| of |file|, returning false on error.
    bool LoadFromFileRegion(base::File file,
        const base::MemoryMappedFile::Region& region);

    // Writes a pack file containing |resources| to |path|. If there are any
    // text resources to be written, their encoding must already agree to the
    // |textEncodingType| specified. If no text resources are present, please
    // indicate BINARY.
    static bool WritePack(const base::FilePath& path,
        const std::map<uint16_t, base::StringPiece>& resources,
        TextEncodingType textEncodingType);

    // ResourceHandle implementation:
    bool HasResource(uint16_t resource_id) const override;
    bool GetStringPiece(uint16_t resource_id,
        base::StringPiece* data) const override;
    base::RefCountedStaticMemory* GetStaticMemory(
        uint16_t resource_id) const override;
    TextEncodingType GetTextEncodingType() const override;
    ui::ScaleFactor GetScaleFactor() const override;
    bool HasOnlyMaterialDesignAssets() const override;

#if DCHECK_IS_ON()
    // Checks to see if any resource in this DataPack already exists in the list
    // of resources.
    void CheckForDuplicateResources(const ScopedVector<ResourceHandle>& packs);
#endif

private:
    // Does the actual loading of a pack file. Called by Load and LoadFromFile.
    bool LoadImpl();

    // The memory-mapped data.
    scoped_ptr<base::MemoryMappedFile> mmap_;

    // Number of resources in the data.
    size_t resource_count_;

    // Type of encoding for text resources.
    TextEncodingType text_encoding_type_;

    // The scale of the image in this resource pack relative to images in the 1x
    // resource pak.
    ui::ScaleFactor scale_factor_;

    // Set to true if the only resources contained within this DataPack are
    // material design image assets.
    bool has_only_material_design_assets_;

    DISALLOW_COPY_AND_ASSIGN(DataPack);
};

} // namespace ui

#endif // UI_BASE_RESOURCE_DATA_PACK_H_
